WO2018192604A1

WO2018192604A1 - Roll stabilizer for a motor vehicle

Info

Publication number: WO2018192604A1
Application number: PCT/DE2018/100124
Authority: WO
Inventors: Sebastian Krüger; Robert Schulze; Andreas Tully
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2017-04-20
Filing date: 2018-02-14
Publication date: 2018-10-25

Abstract

The invention relates to a roll stabiliser (1) for a motor vehicle, comprising a torsion bar (2) with a first and a second distal end (3a, 3b), the two distal ends (3a, 3b) being embodied in a tubular manner and designed to at least partially axially receive a base body (5) of a respective welding bushing (4), the respective welding bushing (4) also comprising a collar (6) that axially rests on the respective distal ends (3a, 3b), on the front side, in an abutment region (10), said collar (6) being weldable to the respective distal ends (3a, 3b). The base body (5) of the respective welding bushing (4) can be pressed axially into the respective distal end (3a, 3b) in order to form a non-positive interference fit, and at least one ventilation channel (8) for evacuating a gas created during the welding process is embodied radially between the base body (5) and the inner diameter of the respective distal end (3a, 3b).

Description

Roll stabilizer for a motor vehicle

The invention relates to a roll stabilizer for a motor vehicle, comprising a torsion bar having a first and second distal end, wherein the two distal ends are tubular and provided to at least partially axially receive a base body of a respective weld bushing.

Usually, each wheel axle of a motor vehicle on a roll stabilizer, which operates on the torsion bar principle. The roll stabilizer is arranged substantially parallel to the vehicle axle and at both ends via a respective

Coupling rod connected to the suspension. Furthermore, the roll stabilizer is provided to stabilize the body structure against unwanted rolling movements about the longitudinal axis of the motor vehicle. Such rolling movements occur, for example, when cornering of the motor vehicle. The rolling motion of the motor vehicle is influenced by the roll stabilizer by the compression movement of the left and right wheel suspension of an axle is coupled together using the roll stabilizer.

DE 10 2013 205 903 A1 discloses a roll stabilizer for a vehicle. The roll stabilizer comprises an actuator for generating a torsional moment about a torsion axis, wherein the actuator has a housing arrangement, and wherein the roll stabilizer has at least one stabilizing component, in particular a torsion bar spring. The stabilization components are usually powder-coated. From DE 10 2015 009 604 A1, a weld-in bushing with a flange is also known, via which the weld-in bushing can be welded to a carrier element. The weld-in bushing has at least one side facing the carrier element during welding, at least one gas emerging through the gas flowing through the recess.

The object of the present invention is to further develop a roll stabilizer of a motor vehicle and in particular to provide a solid and cost-effective connection between a torsion bar and a welding bushing. According to the invention this object is achieved by the roll stabilizer according to claim 1. Expedient developments can be found in the dependent claims.

An inventive roll stabilizer for a motor vehicle comprises a torsion bar having a first and a second distal end, wherein the two distal ends are tubular and intended to at least partially axially receive a main body of a respective weld bushing, wherein the respective weld bush also has a collar which axially abuts the end face in an abutting area at the respective distal end, wherein the collar is weldable to the respective distal end, wherein the main body of the respective weld bushing can be axially pressed into the respective distal end to form a non-positive interference fit; and wherein at least one ventilation channel for discharging a gas generated during welding is formed radially between the base body and the inner diameter of the respective distal end.

Under the term press dressing is basically a cylindrical interference fit as shaft-hub connection to understand in which the main body of the weld bushing, the shaft and the respective distal end of the torsion bar represents the hub. With a press fit occurring longitudinal and transverse forces can be transmitted non-positively or frictionally. As a result, the operational stability of the connection can be increased by an improved support of the bush in the pipe and thereby resulting relief of the weld. A self-centering for uniform power transmission, and a high resistance to impact and alternating stresses are advantageous. The press fit is essentially intended to relieve the weld produced in the welding process. In other words, the body of the weld bush is supported within the respective distal end of the torsion bar, thereby reducing the forces on the weld.

The at least one ventilation channel formed radially between the base body and the inner diameter of the respective distal end ensures adequate ventilation during the welding process. The gases produced during welding On the one hand, they escape radially outwards into the interspace, where they flow into the venting channel and can thus be led away in the direction of the interior of the pipe, starting radially from the weld root. It must be ensured that the venting channel lies or is provided in the area where pore formation is to be expected later. In other words, the venting channel in the overlapping region of the weld, that is provided at the beginning or end of the weld. This ensures compliance with the required weld quality by avoiding pore formation in the weld.

The invention includes the technical teaching that the at least one venting channel is at least partially flattened and formed parallel to the axis of the main body. But it is also conceivable to form the vent channel as a vent groove. Furthermore, a plurality of ventilation channels distributed over the circumference of the main body can be formed. Preferably, the weld-in bushing has an undercut on the face side, in order to produce a primary air channel, which is connected to the venting channel, in the mounted state with the end face of the torsion bar.

The main body preferably has a peripheral annular groove in the abutting region of the welding bushing which comes into abutment at the respective distal end, wherein the main body further has a helical swirl groove which opens into the annular groove in the abutting region for discharging the gas produced during welding. In other words, under the swirl groove to understand a vent channel. It is advantageous that due to the spiral formation of the swirl groove a weakening of the interference fit is avoided. By the circumferential annular groove is also avoided that it comes to gas inclusions in the weld, since the expanding air at any time during the welding process has a deduction in the connected to the annular groove swirl groove. It is also conceivable to form several distributed over the circumference of the body swirl grooves. In particular, the weld-in bushing has an undercut on the face side, which is connected to the swirl groove or annular groove.

Preferably, the base body is cylindrical, wherein the outer diameter of the base body is greater than the inner diameter of the respective distal end, wherein at least the inner diameter is at least partially elastically deformed. For example, the torsion bar may be formed of a first metallic material and the respective welding bushing of a second metallic material, wherein the first metallic material has a higher strength than the second metallic material.

According to a preferred embodiment, the collar or flange of the respective welding bushing can be welded to the end face of the respective distal end of the torsion bar by a fusion welding process. Particularly preferred is the TIG welding process, as it is a relatively fast process and has only a low gas and slag formation in the welding process, whereby this process is particularly clean and the torsion bar does not significantly deform due to the short heat. Alternatively, the weld seam can also be produced by a laser welding method, which also has a reduced formation of gas and slag, and a reduced heat input.

Preferably, the collar of the respective weld bushing is welded circumferentially at the respective distal end. Furthermore, it is conceivable to coat the torsion bar after the welding of the respective collar with the respective distal end by means of powder coating, in order to provide additional protection against external influences and chemical stress on the torsion bar interior, in particular corrosion. In particular, the coating can additionally improve the sealing effect produced by the welding night. Further measures improving the invention will be described in more detail below together with the description of preferred embodiments of the invention with reference to FIGS. Show it

FIG. 1 shows a schematic view of a roll stabilizer according to the invention,

FIG. 2 shows a schematic partially sectioned perspective illustration of a first distal end of a torsion bar of the roll stabilizer according to the invention, FIG. 3 shows a schematic detail sectional view for illustrating the welding bushing received at the first distal end in the pressed-in state, wherein the welding bushing is present in a first embodiment,

Figure 4a is a schematic perspective view of the weld bushing according to

Figure 3, and

Figure 4b is a schematic perspective view of the weld bushing according to a second embodiment.

According to FIG. 1, a roll stabilizer 1 according to the invention for a motor vehicle (not shown here) comprises a torsion bar 2 with first and second distal ends 3a, 3b, wherein the two distal ends 3a, 3b are tubular. According to an alternative embodiment, the roll stabilizer 1 may also comprise an actuator (not shown here) and two torsion bar halves. The roll stabilizer 1 is arranged transversely to the vehicle longitudinal axis and connected at its free ends to - not shown here - wheels or wheel carrier. In FIGS. 2 and 3, the left side of the torsion bar 2 with the first distal end 3a is shown in each case. The - not shown - right side of the torsion bar 2 may be formed analogous to the left side, but it can also be provided an alternative embodiment of the second distal end 3b shown in Figure 1. In FIG. 2, the first distal end 3a of the torsion bar 2 is provided to axially receive a main body 5 of a welding bush 4, the main body 5 being the shaft of the welding bush 4, and the welding bush 4 further comprising a collar 6 formed axially adjacent to the main body 5 comprises, the end face in an abutting region 16 at the first distal end 3a comes to rest axially. According to Figure 3, the main body 5 is cylindrical in shape and received axially by the first distal end 3a. The collar 6 is also cylindrical and has a larger outer diameter than the main body 5. Further, the collar 6 is welded by a weld 1 1 with the first distal end 3a. By welding the weld bush 4 via the collar 6 can the weld bush 4 are welded over a particularly large area and thus firmly with the torsion bar 2. During welding, at least one weld 1 1 is produced, wherein the weld 1 1 is formed circumferentially here and seals a torsion bar interior 14 of the torsion bar 2 against external influences, such as splashing water. The weld 1 1 is in the present case by means of a TIG

Formed welding process, wherein the weld seam 1 1 adjacent peripheral edges of the collar 6 and the first distal end 3a are beveled. The weld bush 4 further has a bore 13 for at least partially receiving at least one - not shown here - fastener, which is connectable to the weld bushing 4, wherein the bore 13 may be formed, for example, as an internal threaded bore.

According to a first embodiment, in order to improve the ventilation during the welding process, a ventilation channel 8 is formed radially between the main body 5 and the inner diameter of the first distal end 3a for discharging a gas produced during welding. During welding, and in particular during fusion welding, gases are produced, in particular from anticorrosion coatings or from alloying elements of metallic materials. Furthermore, in the welding process gases from the welding consumable used and the protective gas, the welding electrode, as well as impurities on the surface of the weld bush or the torsion bar arise. If it comes due to insufficient ventilation to air pockets or gas inclusions in the weld 1 1, the strength of the welded joint between weld bushing 4 and the first distal end 3a is reduced.

Furthermore, the venting channel 8 is provided to allow air to escape during the press-fitting operation of the welding bush 4 into the distal end 3a. This additionally leads to a reduction of the required press-in force for the weld bushing 4.

The outer diameter of the main body 5 is formed larger than the inner diameter of the first distal end 3a. Further, the torsion bar 2 is formed of a first metallic material and the respective weld bush 4 made of a second metallic material. Furthermore, the first metallic material has a higher strength than the second metallic material. The main body 5 penetrates during the press-fitting process in a press-fit direction 12 into the first distal end 3a, wherein the inner diameter of the first distal end 3a is at least elastically deformed. Thus, in the radial direction and in the direction of rotation, a non-positive connection is formed between weld bushing 4 and torsion bar 2. The radial distance between vent channel 8 and the inner diameter of first distal end 3a is decisive for the venting effect during the press-fitting operation and during the welding operation. In Figure 4a, the first embodiment of the weld bush according to Figure 3 is shown in perspective. The venting channel 8 is partially flattened and formed axially parallel to the main body 5, wherein the length of the venting channel 8 substantially corresponds to the length of the main body 5, which forms the interference fit between the main body 5 and inner diameter of the first distal end 3a. By the interference fit between the main body 5, the weld bushing 4 and the first distal end 3a, the weld 1 1 is relieved, thereby increasing the fatigue strength of the welded joint.

According to FIG. 4b, an annular groove 7 is formed circumferentially on the main body 5 on the welding bush 4 according to a second embodiment. The annular groove 7 is arranged in the joint area 10. The main body 5 also has a helically shaped swirl groove 9, which, like the venting channel 8 shown in FIG. 4a, is designed to remove gases generated during welding. For this purpose, the swirl groove 9 opens in the joint area 10 in the annular groove. 7

LIST OF REFERENCE NUMBERS

1 roll stabilizer

2 torsion bar

3a, 3b distal end

4 welding bush

5 basic body

6 fret

7 annular groove

8 venting channel

9 twist groove

10 impact area

1 1 weld

12 pressfit

13 hole

14 Rotating bar interior

Claims

claims

1 . A roll stabilizer (1) for a motor vehicle, comprising a torsion bar (2) having first and second distal ends (3a, 3b), the two distal ends (3a, 3b) being tubular and intended to form a base body (5) of one the respective weld bushing (4) further comprises a collar (6) which comes into abutment axially in an abutment region (10) at the respective distal end (3a, 3b), wherein the Collar (6) with the respective distal end (3a, 3b) is weldable,

characterized in that the base body (5) of the respective welding bushing (4) axially in the respective distal end (3a, 3b) can be pressed to form a non-positive interference fit, wherein radially between the base body (5) and the inner diameter of the respective distal End (3 a, 3 b) at least one venting channel (8) for discharging a gas generated during welding is formed.

2. roll stabilizer (1) according to claim 1,

characterized in that the at least one venting channel (8) is at least partially flattened and formed parallel to the axis of the main body (5).

3. roll stabilizer (1) according to claim 1,

characterized in that the base body (5) in the abutting region (10) of the respective distal end (3a, 3b) abutting the weld bushing (4) has a circumferential annular groove (7), wherein the base body (5) further comprises a helical swirl groove ( 9), which opens into the annular groove (7) in the abutment region (10) for discharging the gas produced during welding.

4. roll stabilizer (1) according to one of the preceding claims,

characterized in that the base body (5) is cylindrical, wherein the outer diameter of the base body (5) is greater than the internal diameter knife of the respective distal end (3a, 3b), wherein at least the inner diameter at least partially elastically deformed.

5. roll stabilizer (1) according to one of the preceding claims,

characterized in that the torsion bar (2) made of a first metallic material and the respective welding bushing (4) are formed from a second metallic material, wherein the first metallic material has a higher strength than the second metallic material.

6. roll stabilizer (1) according to any one of the preceding claims,

characterized in that the collar (6) of the respective weld bush (4) is frontally welded to the respective distal end (3a, 3b) of the torsion bar (2) by a fusion welding process.

7. roll stabilizer (1) according to one of the preceding claims,

characterized in that the collar (6) of the respective welding bushing (4) is welded circumferentially at the respective distal end (3a, 3b).